The amount of stimuli/messages we receive everyday is more than our brains can process. To get by, we rely heavily on shortcuts - principles that allow us to make decisions based on a trigger. For example: based on experience and teachings, we might assume that if a piece of jewelry is expensive it must be very nice and valuable. Expensive (trigger) = good.

When we understand what these principles and triggers are, they can be used to take advantage of peoples automatic response to them.

Reciprocity Rule: if I give you something, you have an internal obligation to give something back to me of equal or greater value.

Contrast Principle: my perception of something is strongly influenced by what I have previously seen, especially immediately before it. If I see a $1,000 shirt right after seeing a $10 shirt, I perceive its value and price point differently than if I were shown the $10 shirt before seeing the $1,000 shirt. Or what if I saw a $100,000 shirt right before seeing the $1,000 shirt?

Rejection-then-Retreat tactic: Offer something large, when denied, retreat to a smaller offer - the one you ultimately wanted to sell. When they feel responsible for the outcome they are more likely to do it. When they "influence" you to a concession/compromise, they are more satisfied and likely to agree to do more business in future.

Commitment and Consistency: two things we are hardwired for. Once we take a stance on something, we are way more likely to act in a way that is consistent with what we have committed to. How to use in business: start potential customers with a small commitment. They will be more inclined to continue in that direction (working with you, supporting that cause, spending money on that type of service/product) in the future. Even better if commitment is public = more likely to stay consistent with that action.

Social Proof: if everyone else is doing it, it must be good/right.

Liking: people are more willing to engage if you seem similar to them, or if they just generally like you. Find/point out way you are similar. Physical appearance should be similar or one step above them. Compliment them. "I am on your side/we are in this together." Association principle: be associated with things they like/want/respect.

Authority Principle: if someone with authority claims it, it must be true.

Scarcity Rule: people don't want to miss out. If it's in limited supply/will expire/might miss out, they will act less rationally.